Thanks, so you dont have an RS reader yet. I will look into this. thanks, mike
On Mon, Aug 30, 2010 at 6:49 PM, Till Heuschmann <theuschm...@googlemail.com> wrote: > Hi Mike, > > I'am working on the R2007 reader which for now just extracts the encoded > data and ignores the rs parity bytes. > So I can provide you some data and give you some hints how to read it. > Attached is the rs data found at offset 0x80 in a .dwg file. The data is > 0x3d8 bytes long and contains 3 blocks of rs data. One block contains 239 > bytes of data and 16 parity bytes. > The blocks are interleaved with a factor of 3. > > The given data starts like this: > B3 01 68 D2 58 01 70 67 51 9E 00 7F 26 01 01 80 CD F0 68 A5 > > ...and so the first rs encoded block starts with: > B3 D2 70 9E 26 80 > > the rest of the data (0x3d8 - (3 * 0xFF) = 0xDB) are padded and not rs > encoded. > > If you need some more data feel free to ask. I will push a first version of > the reader in the next weeks. > > Till > > Am 30.08.2010 08:02, schrieb jamesmikedup...@googlemail.com: >> >> hi all, >> I have started to research into this reed solomon stuff, it does not >> look that hard. >> >> http://en.wikipedia.org/wiki/Reed–Solomon_error_correction >> http://en.wikipedia.org/wiki/BCH_code >> http://en.wikipedia.org/wiki/Berlekamp-Massey_algorithm >> also MIT OCW : >> http://www.youtube.com/watch?v=Nnj9lHePqKM >> >> can you please provide me with a block of pure data that is in RS >> format and the encoding parameters. I am going to work on a decoder. >> >> mike >> >> > > -- James Michael DuPont Member of Free Libre Open Source Software Kosova and Albania flossk.org flossal.org
